Ten to 17 percent of children between the ages of 4 and 16 years meet the criteria for recurrent abdominal pain (RAP) a condition that accounts for at least 5 percent of all pediatric office visits and often leads to significant disability (e.g., school absence). From 30-60 percent of children with RAP will go on to experience similar pain as adults leading to the suggestion that RAP and irritable bowel syndrome (IBS) may be the same syndrome at different developmental stages. Similar to IBS, 20-68 percent of children reporting abdominal pain also experience alterations in bowel patterns (constipation and/or diarrhea). Although the cause(s) of RAP (as well as IBS) are unknown, factors contributing to the symptom experience, including health care seeking, are likely to include both physiological and psychosocial. The relationships among physiologic abnormalities, psychological makeup, and parental responses/behaviors in RAP are largely unexplored (undefined). To study the contributions of these sets of factors and their potential interplay, we propose to compare three groups of children: those with RAP who are referred to tertiary medical attention (RAP-GI); who have RAP but do not seek medical attention beyond their pediatrician (RAP-Ped); and those who do not have RAP symptoms (Controls). Our Specific Aims are to describe and compare among these children (ages 7-10): 1) GI symptoms (abdominal pain and bowel patterns) and functional disability (pain interfering with activity, school absences) using retrospective and prospective symptom measures; 2) autonomic nervous system function (spectral and non-spectral analysis of heart rate variability and urine catecholamines); 3) child and parent pain coping skills, parent modeling and reinforcement of illness behavior; and 4) psychological distress (anxiety, depression, and somatization). Children will be recruited from pediatric practices in Houston. This proposed interdisciplinary study will be the first in children to examine concurrently both physiologic and psychosocial factors related to RAP, and its functional consequences, and to compare these to a sample of children with RAP who do not seek tertiary medical attention. Because so many children with RAP are identified as having IBS when they reach adulthood, this study may provide insight into the developmental progression of this disorder. These data could be used to develop guidelines for use by health care providers to intervene early with children who have this common complaint in order to prevent health care seeking behavior with its attendant financial and emotional cost.